After a 10-month investigation, the Justice Department on Thursday accused the New Orleans Police Department of racial profiling, using excessive force and arresting people without probable cause.

Officers purposefully fired their weapons at 27 African American people from Jan. 2009 to May 2010, the report (PDF) said. The report also accuses officers of targeting gay residents.

At a news conference in New Orleans, DOJ officials pledged to help reform the embattled department. The DOJ isn’t suing the department, but is instead implementing reforms through a court-ordered settlement. New Orleans leaders, also at the news conference, embraced the findings and promised to use the report to alter the “police department’s culture,” the Washington Post reported.

“The problems facing the New Orleans Police Department are serious, wide-ranging, systemic and deeply rooted in the culture of the Department,” said Thomas E. Perez, assistant general of the civil rights division of the DOJ, according to the Washington Post.

The investigation, based on a review of the last two years, officially confirmed what many in New Orleans already believed to be true. After Hurricane Katrina, police misconduct allegations made by New Orleans residents garnered national headlines, tainting the department’s reputation. Further undermining the department’s credibility is the sheer number of officers charged with crimes. Since last year, for example, 20 officers were charged in connection with civilian killings, eight of whom pleaded guilty or have been convicted, the Post reports.

Officials concede reforming the police department will take time. “The findings are sobering and the challenges ahead are daunting, but we will do whatever it takes to make this right,’’ said Mayor Mitch Landrieu.